Vaccine safety: injecting a dose of common sense.

Nonetheless, despite these public health triumphs, vaccines can and do occasionally cause harm. For example, the widespread use of the polio vaccine resulted in vaccine-associated paralytic polio in 1 of every 2.4 million vaccine recipients. For this reason, calls for alternate schedules and cessation of the use of this vaccine began in the mid-1980s. 7 Indeed, the Advisory Committee on Immunization Practices recently recommended that, by January 2000, US children should routinely receive only inactivated polio vaccine for all childhood doses. 8 Vaccines usually result in widespread and dramatic good but also occasional harm. Logically and rationally discerning cause and effect vs speculation or mere temporal associations in regard to vaccine adverse effects allows for wisdom on the part of patient and clinician in deciding whether to receive or promote a given vaccine. 9 As an example of discerning cause and effect, fear of Guillian-Barré syndrome (GBS) due to influenza vaccine is still prevalent. The 1976-1977 influenza vaccine was associated with a statistically increased risk of GBS in some, but not all, groups of recipients. 10 The biologic mechanism for this association has never been determined. During the 1992-1993 and 1993-1994 flu seasons, an excess risk of GBS of approximately 1 in 1 million doses delivered was found only when both seasons were combined for analysis. 11 Whether these statistical associations represent cause and effect remains unclear. Nonetheless, undue fear of such adverse effects prevents some older people who are at high risk of influenza-related hospitalization or death from receiving the vaccine (or some clinicians from recommending vaccination) simply because they fear GBS. Yet, by not accepting the vaccine, such individuals accept risks that are orders of magnitude higher (such as the 20,000 excess deaths or 250,000 excess hospitalizations due to influenza observed nearly every year) than any possible risk from the vaccine. Unfortunately health care workers themselves are not immune to unfounded fears of adverse effects. Despite being at moderate risk for hepatitis B infection and its chronic sequelae, health care workers were among the last to embrace receipt of the plasma-derived vaccine, due to unfounded concerns of possible human immunodeficiency virus contamination. 12,13 Finally, concern arose over the temporal association of varicella vaccination and occurrence of a rash in the first 2 weeks after its administration. Had the vaccine caused the very illness it was supposed to prevent? Polymerase chain reaction testing proved these concerns were unfounded by …